I'm a tabletop skaven general since the 5th edition (Clan Skryre FTW). My group of friends and I have been using The 9th Age ruleset for a couple of months now and are really happy with it, so I thought I'd share the word.
In short, T9A is the spiritual succcessor of the good old Warhammer before Age of Sigmar. Anybody with the experience of the 8th will be at home. It's been balanced by months of testing from thousands of players and it features all the armies we loved including the Chaos Dwarves and the Chaos Ogres.

After months of balancing and testing involving thousands of players, the rules have recently been updated to v1.0. Here's a bit from the release news:
"The free Rule Book, Magic Compendium and 16 Army Books are now available on http://www.the-ninth-age.com/index.php?simple-page. These books represent the cumulative efforts of over 250 volunteer staff members and the input and playtesting from more than 5,000 fans, who were eager to help pick up the pieces after the scene crashed in summer of 2015.
The project was launched in Q3 of 2015 by a team led by the creators of the near-universally-adopted Swe-comp and ETC-comp tournament balancing rules. With their cumulative decades of competitive wargaming experience serving as the guiding hand, and a palpable desire within the fantasy wargaming community, experienced tournament players from all over the world quickly lent their support to help create what has become a comprehensive, balanced, re-imaging of Fantasy Wargaming for a new age, if you will.
This community of stalwarts persevered through a lengthy design and balancing phase, producing thousands of games worth of play-testing data that was compiled and used to inform more than seven book iterations. The result is the most balanced tournament-ready system ever created.
Already The 9th Age has established itself as the tournament standard for competitive fantasy wargaming. As a beta, the Ninth Age has been played at innumerable games and Grand Tournaments worldwide and will be the ruleset for the European Team Competition (ETC) in August 2016. In less than a year The 9th Age has experienced staggering growth and support from all reaches of the globe, filling a void in the fantasy war gaming scene."